1. Field of the Invention
The present invention relates generally to measuring equipment and, more specifically, to a measuring device for measuring various values such as pressure, altitude and temperature etc. and a display method for displaying the measurements electronically, and particularly relates to a highly portable measuring device.
2. Description of the Prior Art
This kind of portable measuring equipment is, for example, incorporated into the body of a wristwatch and has become widely publicized together with the recent increase in participation in outdoor activities. A block view of the essential parts of the configuration of this kind of related portable measuring equipment is shown in FIG. 8. The portable measuring equipment in FIG. 8 is an altimeter that measures pressure and obtains and displays an altitude based on this pressure, and is configured so as to be incorporated integrally with a wristwatch.
Specifically, this portable measuring equipment comprises an oscillating circuit 100 outputting a reference signal using oscillation, a dividing circuit 101 for dividing this reference signal, a pressure sensor 102 for measuring pressure, an A/D converter 103 for converting pressure outputted from the pressure sensor 102 in the form of an analog signal into a digital signal, a pressure/altitude calculator 104 for calculating altitude by known conversion methods based on pressure outputted from the A/D converter 103, a button group 105 consisting of a plurality of buttons for performing arbitrary instructions, a display panel 106 for displaying time and altitude, a display driver circuit 107 for controlling the display panel 106, a ROM 108 for storing measurement processing programs, etc., a RAM 109 for temporarily storing measured values, and a CPU 110 for controlling each of these parts.
With this related portable measuring equipment, normally, a current time obtained via the oscillating circuit 100 and the dividing circuit 101 is displayed at the display panel 106 via the display driver circuit 107. When an altimeter measurement is designated via the button group 105, an altitude obtained via the pressure sensor 102, A/D converter 103 and pressure/altitude calculator 104 is stored in the RAM 109 and this altitude is displayed at the display panel 106 via the display driver circuit 107.
This altitude measurement is carried out in one period selected from a prescribed plurality of periods and this plurality of periods can be switched over between at the button group 105. For example, the normal period is set to five minutes, and a switched over to period is set to five seconds (in the following, taking measurements in the normal period is referred to as normal mode, and taking measurements in the short period is referred to as short period mode). Measurement can then be carried out by switching over between these periods. By switching over between normal mode and short period mode, the user can be aware of trends in the overall change in altitude and the trend of finer changes in altitude at a specific time. As the storage capacity of the RAM 109 is limited, when altitudes measured in normal mode or short period mode exceed the storage capacity, the oldest altitudes are sequentially overwritten with the newest altitude, which is stored.
A method of displaying altitudes acquired in this manner is now described. FIGS. 9A-9C show examples of altitude displayed using the display panel 106. In FIGS. 9A-9C, a first display region 111 displaying a graph showing the altitude in detail and a second display region 112 displaying the current altitude using characters are provided at the display panel 106. At the first display region 111, seven-segment display lines 113 are arranged in parallel in 24 lines. One altitude is then shown as a bar graph by, for example, inverting segments corresponding to the altitude of the segments of one display line 113. The display lines as a whole then show the altitude as a time series going from the left side to the right side in the drawings. For example, the display line 113 at the left end shows the oldest altitude of the altitudes stored in the RAM 109 and the right end of the display line 113 shows the newest altitude. At the second display region 112, seven-segment display sections 114 are arranged in parallel in 3 lines and the newest of the altitudes stored in the RAM 109 is displayed using characters.
FIG. 9A is an example display of altitude measured in normal mode, with altitude measured in a normal period being displayed sequentially along a time series at the first display region, and the newest altitude=112 (m) being displayed at the second display region.
When the measured mode is changed over to the short period mode at the button group 105, the newest altitude is measured using a short period. The newest altitude is then stored in the RAM 109 in place of the oldest altitude and this altitude is displayed at the display panel 106.
FIG. 9B is an example of a display for an altitude measured in the short period mode, where altitude measured in a short period is displayed continuously along a time series so as to follow on from the altitude taken in the normal period at the first display region 111 (here, segments corresponding to the altitude for the short period are given using diagonal lines in FIG. 9 so that altitude measured in the short period can be distinguished from altitude measured in the normal period). A newest altitude of 135 (m) is displayed at the second display region 112.
When measurement in short mode continues, as shown in FIG. 9C, altitude measured in short periods are displayed consecutively at the first display region 111 and a newest altitude of 117 (m) is displayed at the second display region 112.
When normal mode is then later returned to from short period mode as a result of operation of the button group 105 or the elapsing of a prescribed time limit, etc., a new altitude is measured in a normal period and the newly measured altitude is stored in the RAM 109 in place of the oldest altitude. At the same time, altitudes measured in short periods are shown consecutively at the first display region 111 and altitudes newly measured in normal periods are displayed consecutively, as shown in FIG. 9D.
In a further related example disclosed in Japanese Patent Laid-open Publication 7-280651, in a temperature measuring device for measuring temperature of a measurement subject using an amount of infra-red energy emitted from the measurement subject, consecutive measurements are made possible and temperature trends can be understood.
[Problems to be Solved by the Invention]
However, related portable measuring equipment simply stores altitudes measured in normal mode and altitudes acquired in short-period mode together in a single RAM 109 without providing any separation. An altitude acquired in normal mode is therefore lost every time an altitude measured in a short period is stored during changing over from normal mode to short-period mode. This means that while switching back to normal mode, data for measurements of the altitude made in normal mode on previous occasions has already been lost and therefore cannot be re-displayed.
For example, while switching over from FIG. 9C to FIG. 9D, the altitude measured in normal mode of FIG. 9A cannot be redisplayed and only the altitude taken in normal mode following on from the altitude for the short period mode can be displayed as shown in FIG. 9D. This means that the overall trend in the change in altitude measured in normal mode up until this point cannot be seen and this is detrimental to the usefulness of the measured information.
There is also provided related portable measuring equipment where, when a prescribed designation switch is pressed, a measurement is carried out in a prescribed period of time differing from the normal period of time and stored, with the results of this measurement then being displayed when the display switch is pressed. However, in this case also, data measured in the normal period is erased when the amount of data measured in the other period is substantial and the results of measurements in the normal period can therefore not be seen.
In order to solve the aforementioned problems, it is the object of the present invention to provide a portable measuring device where values measured in a specific period can be redisplayed without loss even when the measuring period is switched over.
In addition to substantially the same configuration as the related art, the portable measurement device of the present invention comprises a first storage unit 11 and second storage unit 12 for storing measured values (display information) to be displayed, and a switching unit 13 for switching over the storage content stored in these storage units.
According to this configuration, storage positions of measured values (display information) can be distinguished according to the measurement period and measured values (display information) for a specific period can be displayed at an arbitrary timing. Values measured in a specific period can therefore be re-displayed without loss even when switching over between measuring periods, trends in the changing of overall altitude measured over a specific period can be seen, and the usefulness of the measured information can be improved.
In a specific example of the control content of the switching unit 13, when measuring is carried out using a first period, a measured value (display information) is stored in the first storage unit 11 and displaying is carried out at the display panel 7 based on this measured value (display information), and when measuring is carried out using a second period, a measured value (display information) is stored at the second storage unit 12 and displaying is carried out at the display panel 7 based on this measured value (display information).
When this kind of control is carried out, the value measured (display information) in the first period and the value measured (display information) in the second period can be stored and displayed individually and both measured values (display information) can therefore easily be re-displayed. In particular, copying etc. of information between the first storage unit 11 and the second storage unit 12 is not necessary, control of the storage units is therefore straightforward, and the amount of control required is reduced.
In a further example of the content of the control of the switching unit 13, when measuring is carried out using a first period, a measured value (display information) is stored in the first storage unit 11 and the second storage unit 12 and displaying is carried out at the display panel 7 based on this measured value (display information) stored in the first storage unit 11, when measuring is carried out using a second period, a measured value (display information) is stored at the first storage unit 11 and displaying is carried out at the display panel 7 based on this measured value (display information), and the measured value (display information) stored in the second storage unit 12 can be copied to the first storage unit 11 when switching over from measuring in the second period to measuring in the first period.
The loss of the first period can also be prevented in this case and measured values (display information) can easily be re-displayed. In particular, measured values (display information) are supplied from the first storage unit 11 to the display panel 7 and the display driver circuit 8, control of the output path of the measured values (display information) is therefore straightforward, and this reduces the amount of control required.
Further, a display method of the present invention comprises the steps of measuring with measuring means during a first period, storing a measured value measured in the first period in a first storage unit, measuring using the measuring means in a second period differing to the first period, storing a measured value measured in the second period in a second storage unit, and selecting either the first period or the second period, and displaying the measured value of the first storage unit when the first period is selected, and displaying the measured value of the second storage unit when the second period is selected.
Measured values stored in the respective storage units can therefore be held even while switching over between displaying of measured values stored in the first storage unit and the second storage unit.
Further, a display method of the present invention comprises the steps of measuring with measuring means during a first period, storing a measured value measured in the first period in a first storage unit and a second storage unit, measuring using the measuring means in a second period differing to the first period, storing a measured value measured in the second period in the first storage unit; and copying the measured value of the second storage unit over to the first storage unit while switching over from the second period to the first period, and displaying the measured value of the first storage unit.
In this manner, measured values for a first period are normally held in the second storage means and the measured values for the first period are not lost and can be displayed even when switching over from the second period to the first period.